Funding for this research was provided by:
Department of Education of Hebei Province (NQ2018066)
Chengde Medical University (No. 201802)
National Natural Science Foundation of China (No. 81871437.)
Received: 24 December 2019
Accepted: 19 July 2020
First Online: 1 August 2020
Ethics approval and consent to participate
: Not applicable.
: All the authors agreed for the publications.
: The authors declare that they have no competing interests.